Is 4 year old diesel fuel any good?

[plowhog]

I have about 75 gals of 4 year old diesel fuel and am wondering what I should do with it.

The fuel has been sitting in the fuel tank of a diesel pusher motorhome fuel tank. The fuel tank is 150 gals, or about 1/2 full. The motorhome has been always stored inside an insulated metal building located in a dry climate area.

I don't know if there are any problems with the fuel, and I don't know how I would test it or find out. The motorhome starts and runs fine. But I've read that old diesel fuel can have water or algae in it that clogs filters or does damage. I don't want to do that. Can you help with any ideas?

Here are the options I am considering:

- do nothing and just use it.
- siphon it out, replace with fresh, then slowly use it up/blend it elsewhere by adding small amounts when refueling my tractor.
- siphon it out, use for burn piles (but that's a LOT of fuel for that use!)
- put some additives in it and just use it.

The motorhome engine is a Cummins ISX. It is expensive to work on, even if just buying new filters. So I'd like to avoid causing any maintenance or damage.

Ideas?

 

[Hay Dude]

You are trying to save $300 worth of fuel. The motor home is worth how much? Injectors & repairs are worth how much?

I’d siphon it out pull the fuel lines and add fresh fuel. I made same mistake once and it ruined injectors.

Although it might be “ok”, the chances you are taking are not worth it.

That fuel tank could have just enough water, algae or broken down particles in it to ruin your fuel system. Algae is really bad ju ju

 

[Sawyer Rob]

It would still be good at my house!

SR

 

[masseyrider]

Had a neighbour that always ordered died diesel for farm use. He had a 500 imperial gallon tank that took him at least 2 years to finish.
He really messed up his tractor one spring. He fueled up to do some early cultivating. Gummed everything up. Fuel had rust from the bottom of the tank, water and had just gone bad.
After that he started buying fuel like I do. I'll get 4-6 5 gallon jugs that I know I'll use up in due time.
His savings of a few cents per litre buying bulk cost him thousands. It might have been more if he had refueled both tractors at the same time.

 

[Hay Dude]

Fuel storage is a difficult issue for me. Had storage tanks and with them came contamination problems. Have 80 gallon tank on truck I have to refill 1-2 per week. That’s also a PITA, but it’s always new fuel.

IMO, the only way I would want to store fuel with todays new, super expensive and sensitive fuel systems is if I had a new tank and it was placed in a climate controlled shop.

 

[plowhog]

You are trying to save $300 worth of fuel. The motor home is worth how much?

Makes a lot of sense. Except 75 gals of diesel is a lot more than $300 here.

Separately, I just acquired a 100 gal storage tank and fill-rite pump and meter. Now I need to figure out how to store fuel and cycle it often enough that it doesn't go bad.

 

[sea2summit]

Another option is to pull a sample and have it tested.

Four years without treatments I'm guessing you have a lot of algae. I'm with Haydude, empty it out and reload....and still change your filters soon.

 

[Chewwy]

Last year while clearing out my aunts house after she went into an assisted living facility, we had to get rid of an old fuel oil storage tank. The tank was almost half full of kerosene that had been there since the early 1970s when the oil space heater was removed and replaced with central gas heat.

I found a guy that would take the oil and also remove the 250 gal tank in exchange for the oil. I asked him what he used the oil for. He told me he would filter it, remove any water, and used it in some older tractors. He also said he had been doing this for several years.

 

[Sawyer Rob]

I wouldn't automatically think there's algae in it, I've never had algae in any fuel, and I don't use any additives in my fuel.

I have some really old fuel around and when I decide to use it, my test will be to pump some of it in a clean white pail and look at it. It easy to see if there's anything I don't want in old fuel.

SR

 

[plowhog]

my test will be to pump some of it in a clean white pail and look at it. It easy to see if there's anything I don't want in old fuel.

Makes sense, thanks!

Since the fuel in question powers a very expensive engine, I'm going to pump it all out and examine it. If it seems OK, I will probably find another use for it instead of disposing it. Except I don't have any diesel engine I would be comfortable damaging, of course.

Q- if I slowly blend it with fresh diesel that gets used somewhere else, does that blending "fix" the fuel, or am I just taking longer to eventually get all the bad stuff into the engine that way?